olim Alexander , rex Macedonum , cum exercitu suo ad terras Indorum iter faciebat. - How would you go about translating this sentence?

To start off with, go along the sentence and mark out what case each word is or could be. For example, above 'Alexander' mark 'S', which stands for subject and 'V' for vocative. Similarly, you would do the same for 'rex', as it is in the same case. Going through the line, you can see that 'Macedonum' is in the genitive case, which suggests that rex, and by extension Alexander are both in the nominative case. Moving along the line, we can see that 'exercitu' is in the ablative case due to the cum +abl. Furthermore, we can also see that 'suo' agrees with the 'exercitu' which shows that they are going to be translated together as, 'his army'. Again, moving along the sentence, we can see that the 'ad' +acc means that 'terras' is going to be in the accusative case and 'Indorum' is in the genitive case. Finally 'iter faciebat' go together, as 'iter' can be in one of three cases, you have to use your intuition to see that it will be translated as, 'he was making a journey', therefore it is in the accusative case. Combining everything we have learnt about this sentence, it can be translated like this, 'Once upon a time, Alexander, king of Macedonia, made a journey with his army to the lands of the Indians.'